Deep cuts made in a grass runway to improve drainage may have contributed to a plane crash which killed a key member of David Coulthard's motor racing team, an official accident report said today.

The Second World War Hawker Sea Fury aircraft, piloted by McLaren Mercedes engineer Paul Morgan, 52, overturned on landing at Sywell Aerodrome in Northamptonshire.

The plane tyres had pushed down into the deep cuts, and the ruts created increased the forces that led to the plane pitching on to its nose and then turning over on to its back, said the report from the Air Accidents Investigation Branch.

Mr Morgan, married with a family, was the co-founder of the Ilmor Engineering firm which builds Mercedes' Formula 1 engines and which is based in Brixworth, Northamptonshire.

A day after the May 12, 2001, accident, Coulthard won the Austrian Grand Prix in a car powered by an engine designed by Ilmor.

The report said Mr Morgan was returning to Sywell after a 20-minute flight when the accident happened. His aircraft touched down briefly, became airborne again, and then went into a series of "long skips" before the tail rose and the plane nosed over on to its back.

The AAIB said it was understood the Sywell runway had a long history of poor drainage and a series of parallel cuts in the turf had been made to improve drainage.

In addition, a series of transverse undulations on the runway appeared "to have exacerbated the already present tendency for the aircraft to bounce", said the report.

Coulthard himself had a miraculous escape from a burning jet, which crashed in France in May 2000, killing both pilots.